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Analysis of the seismic effects of the local slope site of Longtoushan market
town in Ludian Ms6.5 earthquake
Article in Frontiers in Earth Sciences · January 2023
DOI: 10.3389/feart.2022.1118079
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TYPE Original Research
PUBLISHED 05 January 2023
DOI 10.3389/feart.2022.1118079
OPEN ACCESS
EDITED BY
Yefei Ren,
Institute of Engineering Mechanics, China
Earthquake Administration, China
REVIEWED BY
Weibing Gong,
University of California, Berkeley,
United States
Ning Zhang,
Anhui Jianzhu University, China
Analysis of the seismic effects of
the local slope site of Longtoushan
market town in Ludian
Ms6.5 earthquake
Liting Du 1, Liguo Jin 2 and Zhenghua Zhou 1*
1
College of Transportation Engineering, Nanjing Tech University, Nanjing, China, 2Institute of Geophysics,
China Earthquake Administration, Beijing, China
*CORRESPONDENCE
Zhenghua Zhou,
bjsmoc@163.com
SPECIALTY SECTION
This article was submitted to Structural
Geology and Tectonics,
a section of the journal
Frontiers in Earth Science
RECEIVED 07 December 2022
ACCEPTED 20 December 2022
PUBLISHED 05 January 2023
CITATION
Du L, Jin L and Zhou Z (2023), Analysis of
the seismic effects of the local slope site of
Longtoushan market town in
Ludian Ms6.5 earthquake.
Front. Earth Sci. 10:1118079.
doi: 10.3389/feart.2022.1118079
COPYRIGHT
© 2023 Du, Jin and Zhou. This is an openaccess article distributed under the terms
of the Creative Commons Attribution
License (CC BY). The use, distribution or
reproduction in other forums is permitted,
provided the original author(s) and the
copyright owner(s) are credited and that
the original publication in this journal is
cited, in accordance with accepted
academic practice. No use, distribution or
reproduction is permitted which does not
comply with these terms.
In the Ludian Ms6.5 earthquake (Yunnan, China), Longtoushan market town and its
vicinity showed significant differences in earthquake damage. To explain this
phenomenon, this paper discusses the local engineering geological conditions,
local topographic effects, and seismic response of the soil layer in Longtoushan
market town. The results show that complex topography and varied engineering
geological conditions will lead to significant differences in ground motion, and
then lead to significant differences in building earthquake damage. Slope
topography has an obvious influence on ground motion. From the foot of
the slope to the top of the slope, the degree of influence gradually increases,
and the influence in different directions is different, as shown: the closer to the
top of the slope, the more significant the difference. This indicates that the
serious damage to buildings built on the slope is caused by the amplification
effect of local terrain and the differential effect of ground motion. Although the site
belongs to Class II site, the near-surface geotechnical properties and their
combination characteristics, the physical state and thickness of the overlying
soil layer, the variation characteristics of shear wave velocity, the non-linear
dynamic characteristics of the soil, and other factors play a decisive role in
the amplification degree of ground motion. The significant difference in ground
motion on the surface of the slope site leads to a significant difference in seismic
damage to buildings on the site. The covering soil layer has a significant effect
on the acceleration response spectrum. The conclusions obtained in this paper
can provide a scientific basis for the site selection of engineering construction
and seismic design of building structures.
KEYWORDS
ground motion, site effect, local topography, response spectrum, ground pulsation
1 Introduction
China has been hit by several destructive earthquakes since 2000, causing heavy casualties
and economic losses. For example, the Wenchuan Ms8.0 earthquake in 2008 caused
more than 100,000 casualties and hundreds of billions of direct economic losses (Peng
et al., 2011). In 2010, the Yushu Ms7.1 earthquake in Qinghai Province killed more than
2000 people (Ni et al., 2010). The Lushan Ms7.0 earthquake in Sichuan Province in
2013 caused hundreds of casualties (Li et al., 2013). The Jinggu Ms6.6 earthquake in
Yunnan Province in 2014 also caused hundreds of casualties and economic losses of
5 billion yuan (Jia et al., 2016). Ludian Ms6.5 earthquake in Yunnan Province on
3 August 2014, caused 617 deaths, 112 missing, and 3,143 injured, and the direct
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10.3389/feart.2022.1118079
the non-uniformity of spatial distribution (Geli et al., 1988; Çelebi
et al., 1991; Shiann-Jong et al., 2009; Sun et al., 2011; Yang et al.,
2018). This shows that for buildings located on complex terrain, it is
necessary to consider local topographic effects in site selection and
seismic design of engineering structures to ensure their safety under
earthquakes.
The detailed seismic damage investigation data, strong motion
records, and engineering geological data of the Ludian earthquake
provide abundant materials for the analysis of local ground motion
effects in Longtoushan Market Town. This paper will study the ground
motion effect of the local slope site in Longtoushan Market Town
through the analysis of local geological conditions, local topographic
effect and seismic response of the soil layer, and then reveal the
mechanism of serious earthquake damage in Longtoushan Market
Town, so as to provide the basis for land planning, the site selection for
engineering construction and building seismic design in Longtoushan
Market Town.
economic losses is 23.578 billion yuan (Hao et al., 2016). In the
Ludian earthquake, the seismic intensity of Longtoushan market
town was IX, which caused serious building damages, as shown in
Figure 1.
In the Ludian earthquake, the strong-motion seismograph
located in the Bureau of Finance of Longtoushan Market Town
recorded a maximum acceleration value of 949 cm/s 2 in the EW
direction, which is the largest peak ground acceleration (PGA)
recorded in the meizoseismal area in the mainland of China so far
(Cui et al., 2014). The investigation of the earthquake damage in the
meizoseismal area shows that there is a large difference in the
earthquake damage to buildings in Longtoushan Market Town,
which is shown as “moderate earthquake but great disaster”. The
study of the abnormal earthquake damage phenomenon is helpful
to reveal the mechanism of the abnormal earthquake damage,
which has important reference value for the revision of the
seismic design code of buildings and the site selection of
construction projects.
Earthquake magnitude, propagation path, and local site
conditions are the main factors affecting earthquake damage
(Mayoral et al., 2019; Jin et al., 2020; Pamuk and Ozer., 2020).
In the case of the Ludian earthquake, a mere Ms6.5 earthquake
would not have been enough to cause such severe damage to
Longtoushan Market Town. The only possible reason for the
significant difference in earthquake damage, under the condition
of a similar transmission path, is that the local site conditions have
a significant impact on earthquake damage.
Local site conditions have a significant influence on earthquake
damage to buildings (Panzera et al., 2018; Brando et al., 2020; Cetin
et al., 2022; Huang et al., 2022). Borcherd et al. (1976) analyzed
the San Francisco earthquake in 1906 and found that the
earthquake damage to buildings located on bedrock or the hard
site was light, while the earthquake damage to buildings located on
soft ground was heavy. They pointed out that the site conditions
have an important influence on earthquake damage. Subsequent
earthquakes also show that site conditions have a significant impact
on building earthquake damage (Estrella et al., 2003). For example,
the Mexico earthquake in 1985, the Jiji earthquake in Taiwan in 1999
(Wang et al., 2002), and the Wenchuan earthquake in Sichuan in
2008 (Bo et al., 2009) all confirmed this conclusion. In addition, the
influence of local terrain on building earthquake damage is mainly
reflected in the amplification of local terrain on ground motion and
2 Engineering geological condition
The Ludian earthquake area is located in the south-central
section of the south-north-trending seismic belt on the eastern
margin of the Qinghai-Tibet Plateau. The geological structure here
is very complex, mainly the NE- and NW- trending fault structures.
The NE-trending fault is mainly the Zhaotong-Ludian fault, which
consists of three secondary faults. The NW-trending fault is mainly
the Baogunao-Xiaohe fault, which consists of several short faults.
Longtoushan Market Town is just in the intersection area of the
Zhaotong-Ludian fault and the Baogunao-Xiaohe fault (Pang et al.,
2016).
According to the investigation of Ludian earthquake damage, the
geomorphic features of Longtoushan market town are mainly
structural erosion canyons and denudating landforms of low
mountain mounds, among which Longquan River and Shaba River
pass through the town. Longtoushan market town is located between
the foot of the mountain and the Longquan River, and the
construction site is mostly the gentle slope landform formed by the
accumulation of rivers. The overlying soil layer of bedrock mainly
includes medium compressible clay containing gravel, pebbled silty
clay, gravel soil, pebble, silty clay, and so on. Such complex topography
and changeable geological conditions will have a significant impact on
FIGURE 1
Earthquake damage in Longtoushan market town.
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time-histories at the observation point. ETNA2 accelerometer
has a GPS time calibration function and has two modes of
continuous recording and trigger recording. The sampling rate
was 200 sps.
Through the observation of ground pulsation at six points, a total
of about 3,000 s of ground pulsation has been recorded. After baseline
correction, digital filtering, and segmental superposition and
averaging of ground pulsation records, the time-history records
that can be used for final analysis are obtained. Then Fourier
transform is applied to the ground pulsation records after
processing. Based on the transfer function method (reference point
spectral ratio method) (Haghshenas et al., 2008), the two horizontal
spectral ratio peaks of the 5 observation points (P2-P6) on the slope
relative to the point P1 at the slope foot and their corresponding
frequencies can be obtained through calculation, as shown in Figure 3.
The calculation results are shown in Table 1.
It can be seen from Table 1 that, the ratios between the peaks of the
spectral ratio of the observation point (P2-P6) on the slope and that of
the observation point P1 are all greater than 1. From the foot of the
slope to the top, the peaks of the spectral ratio become larger. The peak
of the spectral ratio at the slope top (point P6) is the largest, with the
EW direction being 2.835 and the NS direction being 8.422. The
frequencies corresponding to the peaks of the spectral ratio are also
different. The frequency corresponding to the peak of the EW
direction is always larger than that of the NS direction. The
frequency range corresponding to the peak of the EW direction is
5.4 ~ 6.0 Hz, and the NS direction is 4.6 ~ 5.4 Hz. The peaks of the
spectral ratio of the NS direction are always larger than that of the EW
direction. The closer to the top of the slope, the more significant the
difference in the spectral ratio peak.
the ground motion, and then cause significant differences and zoning
of earthquake damage.
3 Analysis of local topographic effect
based on ground pulsation
The houses in Longtoushan market town are mainly built along
the slope, and some of them are seriously damaged by the earthquake,
as shown in Figure 2A. The methods of studying local topographic
effects mainly include the analytical method, numerical simulation,
and experimental study (physical model test and site observation).
With the improvement of instrument observation accuracy and
resolution, site observation, especially ground pulsation
observation, has been widely used in the study of local topographic
seismic effects. The research on the dynamic characteristics of a site
based on ground pulsation (Nurwidyanto et al., 2021; Molnar et al.,
2022) began in the 1960s, and the HVSR spectral ratio method
proposed by Nakamura et al. (Pandey et al., 2018), has been the
most widely used.
To analyze the amplification effect of the slope topography
on ground motion in Longtoushan market town, the author
takes the west slope of the family planning service station of
Longtoushan Market Town as the observation object and carries
out ground pulsation observation. The slope has an angle of about
18°. A total of six observation points were laid for the slope
topography, as shown in Figures 2B, C. The instrument used in
the field test is the ETNA2 accelerometer. The instrument has a
built-in EpiSensor force-balance accelerometer, which can
simultaneously record two horizontal and vertical acceleration
FIGURE 2
Building damage and observation point for ground pulsation on the slope site in Longtoushan Market Town.
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FIGURE 3
The ratio of HVSR between the observation points P2–P6 and P1.
TABLE 1 Spectrum ratio of observation points on the slope.
Measuring point
Direction
Frequency of spectrum ratio (Hz)
Spectral peak value
P2
EW
6.0
1.005
NS
4.6
1.026
EW
5.8
1.044
NS
4.9
1.330
EW
5.7
1.203
NS
5.4
1.825
EW
5.8
1.760
NS
4.9
2.332
EW
5.4
2.835
NS
5.4
8.422
P3
P4
P5
P6
caused by the amplification effect of local terrain and the difference in
ground motion.
To confirm the conclusion obtained by the ground pulsation test,
the finite element method is used to analyze the dynamic
characteristics of the slope topography. Based on ABAQUS®
software, the numerical calculation model was established, as
It can be seen that the slope site has a significant amplification
effect on ground motion. The amplification effect is different from the
foot of the slope to the top of the slope, and the top of the slope has the
largest amplification effect. Meanwhile, the amplification effect in the
slope site also has a significant difference in different directions. It can
be inferred that the serious damage to buildings built on slopes is
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and A12–A16 are close to the free-field results, which indicates that
the influence of the slope can be ignored when the distance from the
slope terrain is more than 2 times the slope height. It can be seen
from Table 1 and Figure 5 that, the numerical simulation is basically
consistent with the pulsation test at the top and foot of the slope, thus
confirming each other.
shown in Figure 4A. According to Liao et al. (1984), the model mesh
size is determined by 1/10 ~ 1/8 of the wavelength that corresponds to
the cutoff frequency. To ensure the accuracy and efficiency of
calculation, the size of the grid is taken as 1 m × 1 m. In this
paper, two conditions are considered: 1) the soil is the completely
weathered rock, with a shear wave velocity of 300 m/s and Poisson’s
ratio of 0.35; ② the soil is the bedrock, with shear wave velocity of
500 m/s and Poisson’s ratio is 0.25. In both cases, the soil is assumed to
be elastic homogeneous isotropic, with mass density of 2,350 kg/m3.
For eliminating the influence of artificial boundaries, the viscoelastic
artificial boundaries were applied to the bottom and the two side
boundaries of the model (Liu et al., 2020). The input is an approximate
δ-pulse incident vertically at the bottom boundary (Liao et al., 1981;
Hao et al., 2014). The approximate δ-pulse and its Fourier amplitude
spectrum are shown in Figure 4B, and the cutoff frequency of the pulse
is 12 Hz.
The horizontal and vertical displacement time histories of each
observation point on the slope terrain are shown in Figures 5A, B.
The authors determined the dynamic amplification coefficient of the
observation point relative to the input pulse (the ratio of the peak
displacement of the observation points to that of the input pulse),
and obtained the variation trend of the dynamic amplification
coefficient of the site along the slope terrain, as shown in
Figure 5C. As can be seen from the figure, as the observation
point gradually rises along the slope, the dynamic amplification
coefficient gradually increases, and the observation point at the top
of the slope has the largest dynamic amplification coefficient. The
dynamic amplification coefficients of the observation points A1–A6
4 Analysis of earthquake response of
slope site
Based on the boreholes (DZK1-DZK6) data and experimental
data corresponding to the six observation points, the onedimensional equivalent linearization method (Astroza et al., 2017;
Rui et al., 2021) is adopted to calculate the site seismic response
at the six observation points. Through this calculation, the
influence of the near-surface covering soil layer on ground
motion is analyzed, and then the earthquake damage to buildings
is discussed. Tables 2, 3 respectively give the soil layer information
and the dynamic characteristic parameters of the soil at the
observation points.
According to the data shown in Table 2, the equivalent shear wave
velocity of each borehole (DZK1-DZK6) at 20 m depth is 273.5, 270.3,
373.4, 347.4, 401.9, and 254.6 m/s respectively; the thickness of the
covered soil layers is 26.0, 59.1, 24.3, 59.0, and 28.3/18.7 m,
respectively. According to Code for Seismic Design of Buildings
(GB 50011–2010) in China, the slope site belongs to Class II
building site.
FIGURE 4
Finite element model of the slope site and the input pulse.
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FIGURE 5
Calculation result of the finite element model of the 2D slope site.
site, we multiply the EW-direction acceleration record by the
reduction coefficient of 0.5 to obtain the input ground motion
from the base. The input ground motion and its response spectrum
are shown in Figure 6. It can be seen that the input ground motion has
a wide frequency band, and the characteristic period is about 0.7 s, rich
in long-period components.
By calculating the horizontal seismic response of each borehole,
the horizontal ground acceleration time-history and response
In the Ludian Ms6.5 earthquake, there was a strong motion
observation station (53LLT) near the DZK1 borehole, which is less
than 10 km away from the epicenter (Cui et al., 2014; Ji et al., 2014).
The station recorded the strong motion time-history in the EW
direction, NS direction, and vertical direction, with the peak
acceleration of 949, 706, and 504 cm/s2, respectively. These are the
maximum acceleration records during the Ludian earthquake.
Therefore, in the one-dimensional seismic response analysis of the
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TABLE 2 Information of the soil layers corresponding to the boreholes.
DZK
Layer
Soil
Depth (m)
Height (m)
Shear wave velocity (m/s)
Density (t/m3)
Soil type number
DZK1
1
Miscellaneous fill
3.2
3.2
185.0
1.87
24
2
Round gravel
11.8
8.6
281.0
2.25
1
3
Round gravel
19.1
7.3
327.0
2.25
2
4
Gravelly sand
23.0
3.9
310.0
2.15
3
5
Gravelly sand
26.0
3.0
310.0
2.15
4
6
Computational base
—
—
758.0
2.50
26
1
Plain fill
1.2
1.2
201.0
1.72
24
2
Round gravel
4.5
3.3
277.0
2.25
12
3
Silt
5.1
0.6
270.0
1.96
5
4
Round gravel
7.0
1.9
328.0
2.25
1
5
Boulder
7.8
0.8
542.0
2.45
26
6
Weathered quartz sand
15.6
7.8
453.0
2.23
6
7
Fault breccia
18.0
2.4
521.0
2.45
26
8
Weathered quartz sand
59.1
41.1
496.0
2.23
6
9
Computational base
—
—
586.0
2.50
26
1
Miscellaneous fill
1.2
1.2
190.0
1.87
24
2
Round gravel
9.9
8.7
379.0
2.25
1
3
Gravel silty clay
12.1
2.2
332.0
1.94
7
4
Dust
13.5
1.4
445.0
2.10
25
5
Broken stone
16.0
2.5
472.0
2.10
25
6
Gravelly sand
21.2
5.2
434.0
2.15
3
7
Gravel silty clay
24.3
3.1
431.0
1.99
9
8
Computational base
—
—
539.0
2.50
26
1
Miscellaneous fill
3.2
3.2
211.0
1.87
24
2
Pebble
4.7
1.5
432.0
2.10
25
3
Round gravel
9.8
5.1
417.0
2.25
1
4
Gravel silty clay
12.5
2.7
375.0
1.94
7
5
silt
13.2
0.7
379.0
1.96
5
6
Gravel silty clay
18.0
4.8
385.0
1.97
8
7
Gravel silty clay
24.0
6.0
385.0
1.99
9
8
Gravel silty clay
30.1
6.1
385.0
2.00
10
9
Weathered limestone
59.0
28.9
462.0
2.20
11
10
Computational base
—
—
510.0
2.50
26
1
Plain fill
1.0
1.0
281.0
1.72
24
2
Round gravel
6.7
5.7
391.0
2.25
12
3
Pebble
7.7
1.0
440.0
2.10
25
4
Round gravel
9.5
1.8
419.0
2.25
13
5
Round gravel
11.5
2.0
419.0
2.25
14
6
Round gravel
15.0
3.5
419.0
2.25
15
DZK2
DZK3
DZK4
DZK5
(Continued on following page)
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TABLE 2 (Continued) Information of the soil layers corresponding to the boreholes.
DZK
DZK6
Layer
Soil
Depth (m)
Height (m)
Shear wave velocity (m/s)
Density (t/m3)
Soil type number
7
Round gravel
21.8
6.8
419.0
2.25
16
8
Weathered limestone
22.5
0.7
545.0
2.20
11
9
Fault gouge
23.1
0.6
392.0
1.86
17
10
Moderately limestone
27.5
4.4
759.0
2.50
26
11
Fault gouge
28.3
0.8
392.0
1.86
17
12
Computational base
—
—
759.0
2.50
26
1
Plain fill
1.0
1.0
165.0
1.72
24
2
Silty clay
4.4
3.4
217.0
1.92
18
3
Clay
6.5
2.1
213.0
1.86
19
4
Gravel silty clay
9.2
2.7
234.0
1.86
20
5
Gravelly sand
10.8
1.6
274.0
2.15
3
6
Clay
11.6
0.8
321.0
1.86
19
7
Gravelly sand
13.7
2.1
259.0
2.15
3
8
Silty clay
15.5
1.8
360.0
2.03
21
9
Silty clay
18.7
3.2
360.0
1.85
22
10
Weathered limestone
26.5
7.8
703.0
2.20
23
11
Computational base
—
—
804.0
2.50
26
the rock and soil near the ground surface and their composition,
the physical state and thickness of the overlying soil, the velocity
variation characteristics, and the non-linear dynamic characteristics of
the soil.
The response spectrum shown in Figure 7B demonstrates that the
response spectra of the ground surface acceleration time-histories that
correspond to different boreholes are also significantly different. The
acceleration response spectra that correspond to DZK1, DZK3, and
DZK5 boreholes are close to each other and close to that of the 53LLT
observation station in the period range of 0.2–0.45 s and 1.4–20 s. The
difference in the response spectrum of ground surface acceleration
corresponding to DZK4 and DZK6 is obvious. When the period is less
than 1.2 s, the response spectrum value of the DZK4 borehole is
smaller than that of the 53LLT observation station, but it is similar
for the rest of the period. For the DZK6 borehole, when the period
is less than 0.9 s, the value of the response spectrum is larger than
that of the 53LLT observation station but similar for the rest
period. In addition, in the period range of 0.65–1.6 s, the response
spectra corresponding to DZK1 and DZK5 boreholes are slightly
higher than that of the 53LLT observation station. It can be seen
that the soil layer close to the ground surface has a significant
influence on the acceleration response spectrum, and it is perioddependent.
From the above analysis, it can be seen that although the
engineering site corresponding to the six boreholes is Class II
site, due to the differences in geotechnical properties and their
combination characteristics, the physical state and layer thickness
of the overlying soil layer, the change of shear wave velocity, and
spectrum at each borehole can be obtained. The peak of horizontal
acceleration of the ground surface at the location of each borehole
and the ratios with the peak of input motion (Peak acceleration ratio)
are shown in Figure 7A. The response spectrum (damping ratio 5%)
for the boreholes is shown in Figure 7B.
It can be seen from Figure 7A that, there are significant differences
in peak values of ground surface acceleration at different observation
points. DZK6 borehole has the maximum peak value of ground
acceleration, and the ratio between it and the peak recorded
(input motion shown in Figure 6) by the 53LLT observation
station is 1.81. The peaks of ground surface acceleration
corresponding to DZK1, DZK3 and DZK5 boreholes are similar,
and all of them are slightly higher than those recorded by
the 53LLT observation station, with the ratios of peak acceleration
are 1.11, 1.16, and 1.12, respectively. Similarly, the ratios of
peak ground surface acceleration corresponding to DZK2 and
DZK4 boreholes are 0.78 and 0.47 respectively, which is close to
the peak acceleration recorded by the 53LLT observation station. It
should be noted that the DZK4 borehole has the lowest peak ground
acceleration which is smaller than the peak of the input ground
motion. The results show that the ground motion amplification
effect at DZK1, DZK3, DZK5 and DZK6 boreholes is higher
than that of 53LLT observation station, especially at the location of
the DZK6 borehole. However, the ground motions at DZK2 and
DZK4 boreholes have different degrees of attenuation, and the
attenuation at the position of the DZK4 borehole is the
most obvious. It can be seen that the amplification effect of the
site on ground motion is jointly determined by the properties of
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TABLE 3 Dynamic non-linear parameters of different soil layers.
Soil type number
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
Soil
Round gravel
Round gravel
Gravelly sand
Gravelly sand
Silt
Weathered sandstone
Gravel silty clay
Gravel silty clay
Gravel silty clay
Gravel silty clay
Weathered limestone
Round gravel
Round gravel
Round gravel
Round gravel
Round gravel
Fault gouge
Silty clay
Clay
Shearing strain γ (10−4)
Modulus ratio
Damping ratio
0.05
0.1
0.5
1
5
10
50
100
G/Gmax
0.9976
0.9952
0.9765
0.9541
0.8061
0.6752
0.2937
0.1721
λ
0.0060
0.0093
0.0252
0.0382
0.0942
0.1301
0.2116
0.2337
G/Gmax
0.9954
0.9909
0.9560
0.9157
0.6847
0.5206
0.1784
0.0980
λ
0.0037
0.0063
0.0212
0.0351
0.0976
0.1350
0.2049
0.2203
G/Gmax
0.9975
0.9950
0.9757
0.9526
0.8007
0.6676
0.2866
0.1673
λ
0.0052
0.0082
0.0232
0.0361
0.0927
0.1298
0.2145
0.2374
G/Gmax
0.9933
0.9868
0.9371
0.8817
0.5984
0.4270
0.1297
0.0693
λ
0.0076
0.0123
0.0365
0.0569
0.1339
0.1717
0.2301
0.2412
G/Gmax
0.9970
0.9940
0.9706
0.9429
0.7675
0.6227
0.2482
0.1417
λ
0.0026
0.0043
0.0143
0.0237
0.0684
0.0985
0.1659
0.1834
G/Gmax
0.9938
0.9878
0.9416
0.8897
0.6173
0.4465
0.1389
0.0746
λ
0.0010
0.0021
0.0112
0.0222
0.0833
0.1235
0.1977
0.2135
G/Gmax
0.9980
0.9960
0.9804
0.9616
0.8337
0.7148
0.3339
0.2004
λ
0.0006
0.0012
0.0055
0.0105
0.0430
0.0722
0.1627
0.1939
G/Gmax
0.9937
0.9876
0.9408
0.8882
0.6137
0.4427
0.1371
0.0736
λ
0.0005
0.0012
0.0077
0.0164
0.0711
0.1098
0.1844
0.2005
G/Gmax
0.9942
0.9885
0.9453
0.8962
0.6333
0.4633
0.1472
0.0795
λ
0.0133
0.0196
0.0470
0.0673
0.1365
0.1690
0.2190
0.2286
G/Gmax
0.9968
0.9937
0.9692
0.9402
0.7586
0.6111
0.2392
0.1358
λ
0.0066
0.0102
0.0275
0.0416
0.0998
0.1345
0.2049
0.2219
G/Gmax
0.9862
0.9728
0.8772
0.7812
0.4166
0.2631
0.0666
0.0345
λ
0.0083
0.0138
0.0431
0.0666
0.1397
0.1667
0.1993
0.2045
G/Gmax
0.9872
0.9746
0.8849
0.7935
0.4345
0.2776
0.0714
0.0370
λ
0.0082
0.0136
0.0427
0.0663
0.1415
0.1702
0.2057
0.2114
G/Gmax
0.9975
0.9950
0.9754
0.9520
0.7987
0.6648
0.2840
0.1655
λ
0.0007
0.0014
0.0065
0.0124
0.0494
0.0807
0.1678
0.1944
G/Gmax
0.9941
0.9833
0.9443
0.8945
0.6291
0.4589
0.1450
0.0782
λ
0.0030
0.0053
0.0192
0.0323
0.0902
0.1229
0.1786
0.1900
G/Gmax
0.9979
0.9959
0.9796
0.9601
0.8280
0.7065
0.3249
0.1940
λ
0.0005
0.0011
0.0055
0.0110
0.0493
0.0854
0.2007
0.2407
G/Gmax
0.9912
0.9826
0.9189
0.8499
0.5311
0.3615
0.1017
0.0536
λ
0.0112
0.0174
0.0464
0.0686
0.1417
0.1725
0.2145
0.2217
G/Gmax
0.9956
0.9912
0.9575
0.9184
0.6924
0.5295
0.1837
0.1012
λ
0.0033
0.0058
0.0207
0.0351
0.1030
0.1454
0.2273
0.2458
G/Gmax
0.9988
0.9975
0.9878
0.9758
0.8897
0.8013
0.4465
0.2874
λ
0.0025
0.0041
0.0124
0.0199
0.0570
0.0856
0.1742
0.2075
G/Gmax
0.9982
0.9964
0.9821
0.9648
0.8458
0.7328
0.3542
0.2152
λ
0.0005
0.0009
0.0047
0.0092
0.0412
0.0720
0.1760
0.2144
(Continued on following page)
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TABLE 3 (Continued) Dynamic non-linear parameters of different soil layers.
Soil type number
20
21
22
23
24
25
26
Soil
Gravel silty clay
Silty clay
Silty clay
Weathered limestone
Filling
Gravel/crushed stone
Bedrock
Shearing strain γ (10−4)
Modulus ratio
Damping ratio
0.05
0.1
0.5
1
5
10
50
100
G/Gmax
0.9989
0.9978
0.9892
0.9787
0.9018
0.8211
0.4786
0.3146
λ
0.0069
0.0101
0.0245
0.0358
0.0835
0.1164
0.2107
0.2453
G/Gmax
0.9961
0.9922
0.9620
0.9268
0.7170
0.5589
0.2022
0.1125
λ
0.0015
0.0027
0.0111
0.0200
0.0673
0.1002
0.1704
0.1875
G/Gmax
0.9991
0.9982
0.9913
0.9828
0.9193
0.8507
0.5326
0.3630
λ
0.0034
0.0052
0.0134
0.0201
0.0504
0.0726
0.1430
0.1719
G/Gmax
0.9941
0.9883
0.9441
0.8940
0.6279
0.4576
0.1444
0.0778
λ
0.0008
0.0018
0.0103
0.0211
0.0858
0.1307
0.2176
0.2366
G/Gmax
0.960
0.950
0.800
0.700
0.300
0.200
0.150
0.100
λ
0.025
0.028
0.030
0.035
0.080
0.100
0.110
0.120
G/Gmax
0.990
0.970
0.900
0.850
0.700
0.550
0.320
0.200
λ
0.004
0.006
0.019
0.030
0.075
0.090
0.110
0.120
G/Gmax
1.000
1.000
1.000
1.000
1.000
1.000
1.000
1.000
λ
0.050
0.050
0.050
0.050
0.050
0.050
0.050
0.050
FIGURE 6
Input ground motion for site seismic response analysis and its response spectrum.
buildings has not been seriously damaged. The seismic response
analysis of the site showed that the amplification effect on the
ground motion at the positions of DZK1, DZK3, DZK5, and
DZK6 boreholes is most significant compared with that at the
location of the DZK4 borehole, while the amplification effect on the
ground motion at the location of DZK2 borehole is relatively small.
This feature is consistent with the actual earthquake damage, that
is, where the amplification of ground motion is stronger, the
damage to the building is heavier. This can show that the
amplification effect of the site on the ground motion has a
significant impact on building damage, and the more significant
the amplification on ground motion, the more serious the building
damage.
the dynamic non-linear characteristics of the soil, the amplification
effect on the ground motion at different borehole position is
significantly different, which will cause a significant difference
in the seismic damage of the house at the location of different
borehole.
Figure 8 shows the damage to the buildings located at different
borehole positions. The locations of boreholes DZK1, DZK3, DZK5,
and DZK6 respectively correspond to the 53LLTobservation station,
the west side of the administration office area, the old block, and the
living area. In these areas, the houses are more severely damaged.
The DZK2 borehole is located on a middle school campus where
the damage to the buildings is relatively light. The DZK4 borehole
is located in a kindergarten where the main structure of the
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10.3389/feart.2022.1118079
FIGURE 7
Site seismic response calculation based on one-dimensional equivalent linearization method.
FIGURE 8
Earthquake damage in Longtoushan Market Town.
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10.3389/feart.2022.1118079
5 Conclusion
Data availability statement
In this paper, the amplification effect of the slope site on
ground motion in Longtoushan Market Town is discussed
through the analysis of local site engineering geological
conditions, local topographic effects and seismic response
analysis of the slope site, and its influence on building
earthquake damage is further investigated. The main findings
and conclusions are as follows:
The original contributions presented in the study are included in
the article/supplementary material, further inquiries can be directed to
the corresponding author.
Author contributions
LD: Validation, Formal analysis, Visualization. LJ:
Conceptualization, Validation, Formal analysis, Data curation,
Visualization, Writing—original draft—review and editing. ZZ:
Software, Data curation, Supervision, Writing—review and editing.
1) Complex topography and variable engineering geological
conditions will lead to significant differences in ground
motion, which in turn will lead to significant differences in
seismic damage to buildings. For slope sites, from the foot of the
slope to the top of the slope, the amplification effect of the site
on ground motion gradually becomes stronger. In different
directions of the same location of the site, the site amplifies
ground motion differently.
2) The strength of the amplification effect of the site on
ground motion is determined by the properties of the rock and
soil near the ground surface and their composition, the physical
state and thickness of the overlying soil layer, the changes of shear
wave speed, and the dynamic non-linear characteristics of the soil.
This will lead to significant differences in ground motion
amplification effects at different locations of the site, which in
turn will lead to significant differences in the seismic damage of
houses located at different locations on the site.
3) The soil layer close to the ground surface has a significant influence
on the ground motion acceleration response spectrum, and it is
period-dependent. The analysis of the site seismic response is
consistent with the actual seismic damage investigation. The
amplification effect of the site on the ground motion has a
significant impact on building damage, and the more significant
the amplification on ground motion, the more serious the building
damage.
Funding
This study is supported by the National Natural Science
Foundation of China (Grant No. U2039208, U1839202).
Conflict of interest
The authors declare that the research was conducted in the
absence of any commercial or financial relationships that could be
construed as a potential conflict of interest.
Publisher’s note
All claims expressed in this article are solely those of the authors
and do not necessarily represent those of their affiliated organizations,
or those of the publisher, the editors and the reviewers. Any product
that may be evaluated in this article, or claim that may be made by its
manufacturer, is not guaranteed or endorsed by the publisher.
References
Astroza, R., César., P., and Ochoa-Cornejo, F. (2017). Site response analysis using onedimensional equivalent-linear method and bayesian filtering. Comput. Geotechnics 89,
43–54. doi:10.1016/j.compgeo.2017.04.004
Haghshenas, E., Bard, P. Y., and Theodulidis, N., (2008). Empirical Evaluation of
microtremor H/V spectral ratio. Bull. Earthq. Eng. 6 (01), 75–108. doi:10.1007/s10518007-9058-x
Bo, J., Qi, W., and Liu, H. (2009). Abnormality of seismic intensity in hanyuan during
wenchuan earthquake. Earthq. Eng. Eng. Vib. 29 (6), 53–64.
Hao, C., Xie, Q., Dai, B., Zhang, H., and Chen, H. (2016). Seismic damage to structures in the
Ms6.5 ludian earthquake. Earthq. Eng. Eng. Vib. 5 (01), 173–186. doi:10.1007/s11803-016-0314-4
Borcherdt, R., and Gibbs, J. (1976). Effects of local geological conditions in the
San Francisco Bay region on ground motions and the intensities of the
1906 earthquake. Bull. Seismol. Soc. Am. (United States) 66 (2), 467–500.
doi:10.1785/bssa0660020467
Hao, M., Zhang, Y., and Zhao, F. (2021). Analysis of slope terrain effect on the properties
of ground motion. Technol. Earthq. Disaster Prev. 16 (2), 229–236. (in Chinese).
Huang, Z. K., Zhang, D. M., Pitilakis, K., Tsinidis, G., Huang, H. W., Zhang, D., et al. (2022).
Resilience assessment of tunnels: Framework and application for tunnels in alluvial deposits
exposed to seismic hazard. Soil Dyn. Earthq. Eng. 162, 107456. doi:10.1016/j.soildyn.2022.107456
Brando, G., Pagliaroli, A., Cocco, G., and Di, B. (2020). Site effects and damage scenarios:
The case study of two historic centers following the 2016 central Italy earthquake. Eng.
Geol. 272, 105647. doi:10.1016/j.enggeo.2020.105647
Ji, K., Wen, R., and Cui, J. (2014). Observation of strong motion and damage
investigation for M_S6.5 ludian earthquake. Technol. Earthq. Disaster Prev. 9 (3), 325–339.
Çelebi, M. (1991). Topographical and geological amplification: Case studies and
engineering implications. Struct. Saf. 10, 199–217. doi:10.1016/0167-4730(91)90015-2
Jia, H., Chen, F., Fan, Y., and Pan, D. (2016). Comparison of two large earthquakes in
China: The ms 6.6 yunnan jinggu earthquake and the ms 6.5 yunnan ludian earthquake in
2014. Int. J. Disaster Risk Reduct. 16, 99–107. doi:10.1016/j.ijdrr.2016.01.006
Cetin, L., Kemal, O., Altun, S., Askan, A., Sezer, A., Kincal, C., et al. (2022). The site
effects in izmir bay of october 30 2020, M7.0 samos earthquake. Soil Dyn. Earthq. Eng. 152,
107051. doi:10.1016/j.soildyn.2021.107051
Jin, K., Lee, J., Lee, K., Kyung, J., and Kim, Y. (2020). Earthquake damage and related
factors associated with the 2016 ML = 5.8 Gyeongju earthquake, southeast Korea.
Geosciences J. 24 (2), 141–157. doi:10.1007/s12303-019-0024-9
Cui, J., Liu, Q., and Duan, J. (2014). Strong-motion recordings of MS6.5 ludian earthquake in
yunnan in 2014 and their preliminary analysis. J. Seismol. Res. 37 (4), 542–548.
Li, Z., Hou, J., and Li, Yang. (2013). Analysis on the characteristics of the MS7. 0 Lushan,
Sichuan province, earthquake hazard on April 20, 2013. Seismol. Geol. 35 (2), 398–410.
Estrella, H., and González, J. (2003). Spac: An alternative method to estimate earthquake
site effects in Mexico city. Geofísica Int. 42 (2), 227–236. doi:10.22201/igeof.00167169p.
2003.42.2.267
Liao, Z. (1984). A finite element method for near-field wave motion in heterogeneous
materials. Earthq. Eng. Eng. Vib. 4 (2), 1–14.
Geli, L., Bard, P. Y., and Jullien, B. (1988). The effect of topography on earthquake
ground motion: A review and new results. BSSA 78 (1), 42–63. doi:10.1785/
bssa0780010042
Frontiers in Earth Science
Liao, Z., Yang, B., and Yuan, Y. (1981). Effects of three-dimensional topography on
earthquake ground motion. Earthq. Eng. Eng. Vib. 1 (1), 56–77.
12
frontiersin.org
Du et al.
10.3389/feart.2022.1118079
Liu, J., Bao, X., and Tan, H. (2020). Seismic wave input method for soil-structure
dynamic interaction analysis based on internal substructure. China Civ. Eng. J. 53 (8),
87–96. (in Chinese).
Pang, W., Yang, R., and Chen, J. (2016). High density resistivity exploration method for
ludian MS6. 5 earthquake in area of longtoushan town in 2014. J. Seismol. Res. 39 (4),
622–629.
Mayoral, J., Asimaki, D., Tepalcapa, S., Wood, C., Roman-de, l., Hutchinson, T., et al.
(2019). Site effects in Mexico City basin: Past and present. Soil Dyn. Earthq. Eng. 121,
369–382. doi:10.1016/j.soildyn.2019.02.028
Panzera, F., Lombardo, G., Imposa, S., Grassi, S., Gresta, S., Catalano, S., et al. (2018).
Correlation between earthquake damage and seismic site effects: The study case of lentini
and carlentini, Italy. Eng. Geol. 240, 149–162. doi:10.1016/j.enggeo.2018.04.014
Molnar, S., Sirohey, A., Assaf, J., Bard, P. Y., Castellaro, S., Cornou, C., et al. (2022). A
review of the microtremor horizontal-to-vertical spectral ratio (MHVSR) method.
J. Seismol. 26, 653–685. doi:10.1007/s10950-021-10062-9
Peng, X., Liu, L., Li, X., and Sun, P. (2011). Study on correlation between building
damage and strong motion parameters in wenchuan earthquake. J. Basic Sci. Eng. 19 (4),
574–582.
Ni, S., Wang, W., and Li, L. (2010). The april 14th, 2010 Yushu earthquake, a devastating
earthquake with foreshocks. Sci. China (Earth Sci. 53 (06), 791–793. doi:10.1007/s11430010-0083-2
Rui, S., and Xiao, M. (2021). A holistic equivalent linear method for site response
analysis. Soil Dyn. Earthq. Eng. 140 (1), 106476. doi:10.1016/j.soildyn.2020.106476
Shiann-Jong, L., Dimitri, K., Bor-Shouh, H., and Jeroen, T. (2009). Effects of topography
on seismic-wave propagation: An example from northern taiwan. BSSA 99 (1), 314–325.
doi:10.1785/0120080020
Nurwidyanto, M., Irhama, C., Zainuri, M., Yuliyanto, G., and Wirasatriya, A. (2021).
Measurement of ground response of semarang coastal region risk of earthquakes by
horizontal to vertical spectral ratio (HVSR) microtremor method. J. Phys. Conf. Ser. 1943
(1), 012033. doi:10.1088/1742-6596/1943/1/012033
Sun, C., Ming, X., and Zhou, M. (2011). Influence of local topography on ground motion
in mountain region of southern gansu province. Northwest. Seismol. J. 33 (4), 331–335.
Pamuk, E., and Ozer, C. (2020). The site effect investigation with using horizontal-tovertical spectral ratio method on earthquake data, south of Turkey. Geotectonics 54 (4),
563–576. doi:10.1134/s001685212004010x
Wang, G., Zhou, X., Zhang, P., and Igel, H. (2002). Characteristics of amplitude and
duration for near fault strong ground motion from the 1999 chi-chi, taiwan earthquake.
Soil Dyn. Earthq. Eng. 22 (1), 73–96. doi:10.1016/s0267-7261(01)00047-1
Pandey, A. K., Roy, P. N. S., Baidya, P. R., and Gupta, A. K. (2018). Estimation of current
seismic hazard using Nakamura technique for the Northeast India. Nat. Hazards 93 (02),
1013–1027. doi:10.1007/s11069-018-3338-4
Frontiers in Earth Science
View publication stats
Yang, Y., Zhu, X., and Yang, Z. (2018). Analytic solution for diffraction of plane P waves
by a circular alluvial valley in wedge-shaped space. Technol. Earthq. Disaster Prev. 13 (4),
810–821.
13
frontiersin.org